Contact: erich.schwienbacher@uibk.ac.at

1. Longevity of seeds in a glacier foreland of the Central Alps - a burial experimentErich Schwienbacher & Brigitta Erschbamer Institute of Botany University of Innsbruck 15th annual meeting of the Section Plant Population Biologie of the Society for Ecology, May 2002 Contact: erich.schwienbacher@uibk.ac.at

2. Introduction Seed germination: important life history trait • Seed banks: important sources for the regeneration

3. Lack of knowledge about longevity of alpine seeds Introduction • Controversial opinions about the glacier foreland  burial experiment

4. persistence of seeds is dependent on size (1) small seeds  long-lived (2) big seeds  short-lived Hypotheses • but independently of the size (3) hard-coated seeds  long-lived

5. ROTMOOSFERNERTyrol, Austria burial site glacier foreland 2300 - 2400 m a.s.l. 46°49‘N 11°02‘E

6. Species used for the experiment • Saxifraga aizoides • Saxifraga oppositifolia • Linaria alpina • Achillea moschata • Artemisia genipi • Trifolium pallescens • Oxyria digyna • Geum reptans • Anthyllis alpestris

7. Types of seeds • small • big Anthyllis alpestris Saxifraga aizoides • hard-coated Trifolium pallescens

8. Design of experiment • 4 groups • 9 species • 100 seeds • 5 replicates fresh 1-year 2-year field experiment 5-year

9. Protocol of the burial experiment and the germination test fresh seeds germination rate ‚growth chamber‘ growth chamber: germination test - 100 days scarification of hard-coated seeds germination rate ‚scarified seeds‘ growth chamber: germination test - 10 days stratification (+ 4°C)

10. Protocol of the burial experiment and the germination test field experiment 1-year burial stratification + germination in the field germination rate ‚field‘ fresh seeds stratification (+ 4°C) germination rate ‚growth chamber‘ growth chamber: germination test - 100 days scarification of hard-coated seeds germination rate ‚scarified seeds‘ growth chamber: germination test - 10 days

11. Protocol of the burial experiment and the germination test 2-year burial 5-year burial field experiment fresh seeds 1-year burial stratification (+ 4°C) stratification + germination in the field germination rate ‚field‘ growth chamber: germination test - 100 days germination rate ‚growth chamber‘ scarification of hard-coated seeds growth chamber: germination test - 10 days germination rate ‚scarified seeds‘

12. Results • fresh seeds

13. Results • fresh seeds: •  high germination rates • (42.7 % ± 34.7) • 1-year burial: •  mostly low germination rates • (10.6 % ± 13.8) • but: increasing germination rates • with increasing seed weight

14. Results • 1-year burial Regression: seed weight/number of seedlings R²=0.82 log no. of seedlings log seed weight

15. Results hard-coated seeds: Linaria alpina, Trifolium pallescens, Anthyllis alpestris • 1-year burial • fresh seeds

16. or  secondary dormancy takes place ? Conclusions (1) hard-coated seeds •  potential to form persistent seed banks (2) big seeds •  germinate after the first year in the field (3) small seeds  loose their viability during the first winter ?

17.  • 2-year burial • 5-year burial Future ? • For how long do seeds persist • in the glacier foreland?

18. Acknowledgements • Jürg Stöcklin • Colleagues of the Univ. Innsbruck • Austrian Academy of Science Thank you for your attention! Contact: erich.schwienbacher@uibk.ac.at